Linked Life Data

623238

Source:http://linkedlifedata.com/resource/pubmed/id/623238

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1978-3-21
pubmed:abstractText
The recent characterization of a vesicular microvillous plasma membrane preparation from human placenta has made possible study of the characteristics of amino acid transport by the isolated membrane. Variation of medium osmolality demonstrated that alpha-aminoisobutyric acid (AIB) is taken up virtually entirely into a vesicular space. Vesicular volume was determined from equilibrium uptake of three dissimilar nonamino acid substrates, all of which gave a common value. Temperature dependence, saturability, specificity, and similarity of kinetic constants all indicated that AIB uptake by the vesicles resembles that by whole villous tissue. AIB uptake was stimulated specifically by an inward sodium gradient and unaffected by an outward potassium gradient. The persistence of stimulation up to 2 h after the gradient was established could be correlated with the slow equilibration of sodium across the membrane. AIB exodus could be studied with minimal problems of substrate recapture by using preloaded membrane vesicles bound tightly to cellulose ester filters to facilitate transfer to fresh medium. The exodus process was saturable with a Km considerably greater than that for entry.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
234
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C27-35
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1978
pubmed:articleTitle
Placental amino acid uptake. IV. Transport microvillous membrane vesicles.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.